James Van Allen | |
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 Van Allen at theNational Air and Space Museum, 1977 | |
| Born | James Alfred Van Allen (1914-09-07)September 7, 1914 |
| Died | August 9, 2006(2006-08-09) (aged 91) Iowa City, Iowa, US |
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| Scientific career | |
| Fields | Space science |
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| Thesis | Absolute cross-section for the nuclear disintegration H2 + H2 → H1 + H3 and its dependence on bombarding energy (1939) |
| Doctoral advisor | Alexander Ellett |
| Doctoral students | |
| Other notable students | Nicholas M. Smith Robert Ellis |
James Alfred Van Allen (September 7, 1914 – August 9, 2006) was an Americanspace physicist at theUniversity of Iowa. He was instrumental in establishing the field ofmagnetospheric research in space.
TheVan Allen radiation belts were named after him, following his discovery usingGeiger–Müller tube instruments on the 1958satellites (Explorer 1,Explorer 3, andPioneer 3)[2][3][4] during theInternational Geophysical Year. Van Allen led the scientific community in putting scientific research instruments on space satellites.
James Van Allen was born on September 7, 1914, on a small farm nearMount Pleasant, Iowa.[5] As a child, he was fascinated by mechanical and electrical devices and was an avid reader ofPopular Mechanics andPopular Science magazines. He once horrified his mother by constructing aTesla coil that produced foot-long sparks and caused his hair to stand on end.[6][7]
A fellowship allowed him to continue studying nuclear physics at theCarnegie Institution in Washington, D.C., where he also became immersed in research ingeomagnetism,cosmic rays,auroral physics and the physics of Earth's upper atmosphere.[8]
In August 1939, Van Allen joined the Department of Terrestrial Magnetism (DTM) of theCarnegie Institution in Washington, D.C. as a Carnegie Research Fellow. In the summer of 1940, he joined DTM's national defense efforts with his appointment to a staff position in Section T with theNational Defense Research Committee (NDRC) in Washington, D.C., where he worked on the development of photoelectric and radioproximity fuzes, which are detonators that increase the effectiveness of anti-aircraft fire. Another NDRC project later became the atomic bombManhattan Project in 1941. With the outbreak of World War II, the proximity fuze work was transferred to the newly createdApplied Physics Laboratory (APL) ofJohns Hopkins University in April 1942.[9] He worked on improving the ruggedness of vacuum tubes subject to the vibration from a gun battery. The work at APL resulted in a new generation of radio-proximity fuses for anti-aircraft defense of ships and for shore bombardment.
Van Allen was commissioned as a U.S. Navy lieutenant in November 1942 and served for 16 months on a succession of South Pacific Fleet destroyers, instructing gunnery officers and conducting tests on using the new and then strictly secret artillery fuses. He was an assistant staff gunnery officer on the battleshipUSS Washington when the ship successfully defended itself against a Japanese attack during theBattle of the Philippine Sea, (June 19–20, 1944). For his actions at the Pacific, Van Allen was awarded fourbattle stars.[10] He was promoted to lieutenant commander in 1946. "My service as a naval officer was, far and away, the most broadening experience of my lifetime," he wrote in a 1990 autobiographical essay.[6]
Discharged from the Navy in 1946, Van Allen returned to civilian research at APL. He organized and directed a team at Johns Hopkins University to conduct high-altitude experiments, usingV-2 rockets captured from the Germans at the end ofWorld War II. Van Allen decided a smallsounding rocket was needed for upper atmosphere research. The AerojetWAC Corporal and the Bumblebee missile were developed under a US Navy program. He drew specifications for theAerobee sounding rocket and headed the committee that convinced the U.S. government to produce it. The first instrument-carrying Aerobee was the A-5, launched on March 5, 1948, fromWhite Sands, New Mexico, carrying instruments for cosmic radiation research, reaching an altitude of 117.5 km.
Van Allen was elected chairman of theV-2 Upper Atmosphere Panel on December 29, 1947. The panel was renamedUpper Atmosphere Rocket Research Panel on March 18, 1948; then Rocket and Satellite Research Panel on April 29, 1948. The panel suspended operations on May 19, 1960, and had a reunion on February 2, 1968.[11]
Cmdr. Lee Lewis, Cmdr. G. Halvorson,S.F. Singer, and James A. Van Allen developed the idea for theRockoon on March 1, 1949, during the Aerobee rocket firing cruise on the research vesselUSSNorton Sound.
On April 5, 1950, Van Allen left the Applied Physics Laboratory, to accept aJohn Simon Guggenheim Memorial Foundation research fellowship at theBrookhaven National Laboratory. The following year (1951) Van Allen accepted the position as head of the physics department at the University of Iowa. Before long, he was enlisting students in his efforts to discover the secrets of the wild blue yonder and inventing ways to carry instruments higher into the atmosphere than ever before. By 1952, Van Allen was the first to devise a balloon-rocket combination that lifted rockets on balloons high above most of the Earth's atmosphere before firing them even higher. The rockets were ignited after the balloons reached an altitude of 16 kilometers.
AsTime magazine later reported, "Van Allen’s ‘Rockoons’ could not be fired in Iowa for fear that the spent rockets would strike an Iowan or his house." So Van Allen convinced the U.S. Coast Guard to let him fire his Rockoons from the icebreakerEastwind that was bound forGreenland. "The first balloon rose properly to 70,000 ft., but the rocket hanging under it did not fire. The second Rockoon behaved in the same maddening way. On the theory that extreme cold at high altitude might have stopped the clockwork supposed to ignite the rockets, Van Allen heated cans of orange juice, smuggled them into the third Rockoon’s gondola, and wrapped the whole business in insulation. The rocket fired."
In 1953, the Rockoons and their science payloads fired offNewfoundland detected the first hint of radiation belts surrounding Earth. The low-cost Rockoon technique was later used by theOffice of Naval Research and the University of Iowa research groups in 1953–1955 and 1957, from ships at sea between Boston andThule, Greenland.[12][13]
In 1954, in a private discussion about theRedstone project withErnst Stuhlinger,Wernher von Braun expressed his belief that they should have a "real, honest-to-goodness scientist" involved in their little unofficial satellite project. Stuhlinger followed up with a visit to Van Allen at his home inPrinceton, New Jersey, where Van Allen was on sabbatical leave from Iowa to work onstellarator design. Van Allen later recounted, "Stuhlinger’s 1954 message was simple and eloquent. By virtue of ballistic missile developments atArmy Ballistic Missile Agency (ABMA), it was realistic to expect that within a year or two a small scientific satellite could be propelled into a durable orbit around the earth (Project Orbiter).... I expressed a keen interest in performing a worldwide survey of the cosmic-ray intensity above the atmosphere."[14]: 2
In 1950 an event occurred that began small but was to affect the future of Van Allen and all his countrymen. In March, British PhysicistSydney Chapman dropped in on Van Allen [and] remarked that he would like to meet other scientists in the Washington area. Van Allen got on the phone, soon gathered eight or ten top scientists (Lloyd Berkner,S. Fred Singer, andHarry Vestine) in the living room of his small brick house. ‘It was what you might call a pedigreed bull session,’ he says.... The talk turned to geophysics and the two ‘International Polar Years’ that had enlisted the world’s leading nations to study the Arctic and Antarctic regions in 1882 and 1932. Someone suggested that with the development of new tools such as rockets, radar and computers, the time was ripe for a worldwide geophysical year. The other men were enthusiastic, and their enthusiasm spread around the world from Washington DC. From this meeting Lloyd Berkner and other participants proposed to the International Council of Scientific Unions that an IGY be planned for 1957–58 (during the maximum solar activity).... TheInternational Geophysical Year (1957–58) stimulated the U.S. Government to promise earth satellites as geophysical tools. The Soviet government countered by rushing its Sputniks into orbit. The race into space orSpace Race may be said to have started in Van Allen’s living room that evening in 1950.
— Time, 1959
In 1955, the U.S. announcedProject Vanguard as part of the US contribution to theInternational Geophysical Year. Vanguard planned to launch an artificial satellite into an orbit around the Earth. It was to be run by the US Navy and developed fromsounding rockets, which had the advantage of being primarily used for non-military scientific experiments.[15]
A symposium on "The Scientific Uses of Earth Satellites" was held on January 26 and 27, 1956 at theUniversity of Michigan under sponsorship of the Upper Atmosphere Rocket Research Panel, chaired by Dr. Van Allen. 33 scientific proposals were presented for inclusion in the IGY satellites. Van Allen's presentation highlighted the use of satellites for continuing cosmic-ray investigations. At this same time his Iowa Group began preparations for scientific research instruments to be carried by 'Rockoons' andVanguard for the International Geophysical Year. Through "preparedness and good fortune," as he later wrote, those scientific instruments were available for incorporation in the 1958Explorer andPioneer IGY launches.
The May 4, 1959, issue ofTime magazine credited James Van Allen as the man most responsible for giving the U.S. "a big lead in scientific achievement." They called Van Allen "a key figure in the cold war’s competition for prestige. .... Today he can tip back his head and look at the sky. Beyond its outermost blue are the world-encompassing belts of fierce radiation that bear his name. No human name has ever been given to a more majestic feature of the planet Earth."
James Van Allen, his colleagues, associates and students at The University of Iowa continued to fly scientific instruments on sounding rockets, Earth satellites (Explorer 52 / Hawkeye 1), and interplanetary spacecraft including the first missions (Pioneer program,Mariner program,Voyager program,Galileo spacecraft) to the planets Venus, Mars, Jupiter, Saturn, Uranus, and Neptune. Their discoveries contributed important segments to the world's knowledge of energetic particles, plasmas and radio waves throughout theSolar System.
Van Allen was the principal investigator for scientific investigations on 24 Earth satellites and planetary missions.
Van Allen stepped down as the head of the department of physics and astronomy in 1985, but continued working at the University of Iowa as the Carver Professor of Physics, emeritus. On October 9, 2004, the University of Iowa and the UI Alumni Association hosted a celebration to honor Van Allen and his many accomplishments, and in recognition of his 90th birthday. Activities included an invited lecture series, a public lecture followed by a cake and punch reception, and an evening banquet with many of his former colleagues and students in attendance. In August 2005, an elementary school bearing his name opened inNorth Liberty, Iowa. There is also a Van Allen elementary school in Escalon, CA.[16]
In 2009, Van Allen's boyhood home in Mt. Pleasant, once maintained as a museum, was slated to be demolished.[17] The new owner, Lee Pennebaker, chose not to demolish the home. It was donated to the Henry County Heritage Trust, which plans to move the house next to the old Saunders School which will be the home of the Henry County museum.[18]
Van Allen's wife of 61 years was Abigail Fithian Halsey II of Cincinnati (1922–2008). They met at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) during World War II. They were married October 13, 1945, in Southampton, Long Island. Their five children are Cynthia, Margot, Sarah, Thomas, and Peter.[19]
On August 9, 2006, James Van Allen died at University Hospitals inIowa City fromheart failure.[20][21]
Professor Van Allen and his wife Abigail are buried in Southampton, New York, where Mrs. Van Allen was born and the couple were married.[22]
Abigail M. Foerstner wrote a biographyJames van Allen: The First Eight Billion Miles, published byUniversity of Iowa Press in 2007 with a paperback edition in 2009.[23][24][25]
The Van Allen Probes, initially the Radiation Belt Storm Probes (RBSP), were renamed in 2012 in honor of Dr. Van Allen.[31] Managed by NASA'sGoddard Space Flight Center[31] and implemented by theApplied Physics Laboratory (APL) at Johns Hopkins University,[32] the mission was a part of theLiving With a Star program. Designed for a two-year primary mission, the probes exceeded expectations by operating for seven years, demonstrating significant resilience against radiation in Earth's belts.[32]
In collaboration with theBalloon Array for RBSP Relativistic Electron Losses (BARREL), the probes studied particles from the belts reaching Earth's atmosphere.[33] Launched on August 30, 2012, aboard anAtlas V 401 rocket contracted to United Launch Alliance (ULA), the mission was initially delayed due to weather andHurricane Isaac.[34]
The mission concluded with the deactivation of Van Allen Probe B in July 2019 and Probe A in October 2019,[32] following the lowering of their orbits to facilitate atmospheric reentry by 2034 as a measure against orbital debris.[35]
The Van Allen Probes significantly advanced the understanding of space weather and its impact on Earth. Key discoveries included the dynamics of the Van Allen radiation belts and the role of solar activity in influencing space weather. The mission's findings highlighted how these radiation belts swell and shrink over time, responding to solar eruptions and impacting terrestrial phenomena like auroras, satellite functionality, power grids, and GPS communications.[36]
A notable discovery in February 2013 was the transient appearance of a third Van Allen Radiation Belt, which lasted a few weeks and provided new insights into the belts' structure and dynamics.[37] The probes also revealed the long-term behavior of Earth's ring current, a major component of the magnetosphere. Findings indicated a persistent, substantial ring current around Earth even during non-storm times, carried by high-energy protons. During geomagnetic storms, the enhancement of the ring current was shown to be due to low-energy protons entering the near-Earth region, challenging previous understandings.[38]
Eighty years after the Second Byrd Expedition, the Balloon Array for RBSP Relativistic Electron Losses (BARREL), a NASA mission began to study Earth's Van Allen radiation belts at the Antarctic (South Pole) managed byDartmouth College. BARREL launched 20 balloons from Antarctica during each of two balloon campaigns in January–February 2013 and December 2013 – February 2014. This scientific data will complement the Van Allen Probes data over the two-year mission.
This article incorporatespublic domain material from websites or documents of theNational Aeronautics and Space Administration.
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